Near Silent (Boom) Supersonic Ninja Star Jet?
A team of researchers at the University of Miami has received $100,000 in NASA funding to further develop their ninja-star-looking bi-directional flying wing jet, which rotates 90 degrees in flight to achieve supersonic speeds with virtually no ground-observable sonic boom. The aircraft design is symmetrical along its longitudinal axis and its lateral axis, but one is longer than the other. It has two cockpits, each at one end of one axis, separated by 90 degrees. In flight at subsonic speed, the aircraft uses its longer axis as its wings, with its tips folded up into winglets. The aircraft transitions to supersonic flight by folding down the wingtips and using aerodynamic forces to rotate 90 degrees around centrally mounted twin turbofans. Once rotated, the shorter axis, an airfoil highly optimized for supersonic flight, serves as the wing.
The researchers have run computer models showing that the shorter wing delivers to ground level no observable supersonic boom when traveling at speeds near 1.5 Mach and 2.0 Mach. Transition from subsonic to supersonic configurations would require a 5-second rotation that researchers estimate would produce low level forces that passengers would find difficult to observe. That said, the research will not lead to supersonic passenger jets flying the skies in the next few years. Any application of the technology would likely see flight no sooner than 20 years from now. And that timeframe suggests other technological advances and aerodynamic modifications would evolve and be incorporated along the way. But the research team has looked at simulated versions of the aircraft operating as a business jet. And drone markets seeking the ability to use supersonic speeds and near-silent stealth could help press development.